Three-dimensional (3d) semiconductor memory device

ABSTRACT

A 3D semiconductor memory device includes a peripheral circuit structure including a first row decoder region, a second row decoder region, and a control circuit region between the first and second row decoder regions, a first electrode structure and a second electrode structure on the peripheral circuit structure, spaced apart in a first direction, and each including stacked electrodes, a mold structure on the peripheral circuit structure between the first and second electrode structures and including stacked sacrificial layers, vertical channel structures penetrating the first and second electrode structures, a separation insulating pattern provided between the first electrode structure and the mold structure and penetrating the mold structure, and a separation structure intersecting the first electrode structure in the first direction and extending to the separation insulating pattern, wherein a maximum width of the separation insulating pattern in a second direction is greater than a maximum width of the separation structure in the second direction.

CROSS-REFERENCE TO RELATED APPLICATION

This is a Continuation of U.S. application Ser. No. 17/095,821, filedNov. 12, 2020, and a claim of priority under 35 U.S.C. § 119 is made toKorean Patent Application No. 10-2020-0059307, filed on May 18, 2020, inthe Korean Intellectual Property Office, the disclosures of which arehereby incorporated by reference in their entireties.

BACKGROUND

Embodiments of the inventive concept relate generally to semiconductordevices. More particularly, embodiments of the inventive concept relateto three-dimensional (3D) semiconductor memory devices having improveddesign efficiency.

Semiconductor devices have been highly integrated to provide excellentperformance and low manufacturing costs. The integration density ofsemiconductor devices directly affects the costs of the semiconductordevices, thereby resulting in a demand of highly integratedsemiconductor devices. The integration density of typicaltwo-dimensional (2D) or planar semiconductor devices may be mainlydetermined by an area where a unit memory cell occupies. Therefore, theintegration density of the typical 2D semiconductor devices may begreatly affected by a technique of forming fine patterns. However, sinceextremely high-priced apparatuses are needed to form fine patterns, theintegration density of 2D semiconductor devices continues to increasebut is still limited. Thus, three-dimensional (3D) semiconductor memorydevices have been developed to overcome the above limitations. 3Dsemiconductor memory devices may include memory cellsthree-dimensionally arranged.

SUMMARY

Embodiments of the inventive concept provide a three-dimensional (3D)semiconductor memory device having improved design efficiency.

According to an aspect of the inventive concept, a 3D semiconductormemory device may include; a peripheral circuit structure including afirst row decoder region, a second row decoder region, and a controlcircuit region between the first row decoder region and the second rowdecoder region, a first electrode structure and a second electrodestructure on the peripheral circuit structure, wherein the firstelectrode structure and the second electrode structure are spaced apartin a first direction and each respectively includes stacked electrodes,a mold structure on the peripheral circuit structure, wherein the moldstructure is disposed between the first electrode structure and thesecond electrode structure and includes stacked sacrificial layers,vertical channel structures penetrating the first electrode structureand the second electrode structure, a separation insulating patternprovided between the first electrode structure and the mold structureand penetrating the mold structure, and a separation structureintersecting the first electrode structure in the first direction andextending to the separation insulating pattern, wherein a maximum widthof the separation insulating pattern in a second direction is greaterthan a maximum width of the separation structure in the seconddirection.

According to an aspect of the inventive concept, a 3D semiconductormemory device may include; a substrate, an electrode structure includingelectrodes stacked on the substrate, a mold structure intersecting theelectrode structure and extending in a first direction, the moldstructure dividing the electrode structure into a first electrodestructure and a second electrode structure in a second direction andextending in the first direction, vertical channel structurespenetrating the first electrode structure and the second electrodestructure, a separation insulating pattern provided between the firstelectrode structure and the mold structure, and penetrating the moldstructure, and a separation structure intersecting the first electrodestructure in the second direction and extending to the separationinsulating pattern, wherein the mold structure comprises stackedsacrificial layers respectively disposed at same levels as the stackedelectrodes, and an end of the separation structure is surrounded by theseparation insulating pattern when viewed in plan.

According to an aspect of the inventive concept, a 3D semiconductormemory device may include; a first substrate, a peripheral circuitstructure on the first substrate, the peripheral circuit structureincluding a first row decoder region, a second row decoder region, and acontrol circuit region between the first row decoder region and thesecond row decoder region, a second substrate on the peripheral circuitstructure, the second substrate including a first semiconductor layerand a second semiconductor layer, a first electrode structure and asecond electrode structure respectively provided on the firstsemiconductor layer and the second semiconductor layer, wherein thefirst electrode structure and the second electrode structure are spacedapart in a first direction and respectively include comprises stackedelectrodes, the first electrode structure having a stair-steppedstructure adjacent to the first row decoder region, and the secondelectrode structure having a stair-stepped structure adjacent to thesecond row decoder region, a mold structure on the peripheral circuitstructure, the mold structure disposed between the first electrodestructure and the second electrode structure, and the mold structureincluding stacked sacrificial layers, a first vertical channel structurepenetrating the first electrode structure to connect the firstsemiconductor layer, a second vertical channel structure penetrating thesecond electrode structure to connect the second semiconductor layer, aseparation insulating pattern provided between the first electrodestructure and the mold structure and penetrating the mold structure, aseparation structure intersecting the first electrode structure in thefirst direction and extending to the separation insulating pattern, theseparation structure dividing the electrode of the first electrodestructure into segments in a second direction, an interlayer insulatinglayer covering the first electrode structure and the second electrodestructure, bit lines provided on the interlayer insulating layer andelectrically connected to the first vertical channel structure and thesecond vertical channel structure and upper interconnection lineselectrically connected to the stair-stepped structure of the firstelectrode structure and the stair-stepped structure of the secondelectrode structure. Each of the first vertical channel structure andthe second vertical channel structure may include; a verticalsemiconductor pattern vertically extending from the second substrate anda data storage layer disposed between the vertical semiconductor patternand the stacked electrodes. The control circuit region may include afirst peripheral transistor provided under the first electrodestructure, a second peripheral transistor provided under the secondelectrode structure, and a lower interconnection line crossing under themold structure, and the first peripheral transistor electricallyconnecting the second peripheral transistor through the lowerinterconnection line.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept will become more apparent upon consideration ofthe following detailed description with reference to the accompanyingdrawings.

FIG. 1 is a perspective view illustrating a three-dimensional (3D)semiconductor memory device according to embodiments of the inventiveconcept.

FIG. 2 is a plan (or top-down) view illustrating a 3D semiconductormemory device according to embodiments of the inventive concept.

FIGS. 3A, 3B, 3C, 3D and 3E are cross-sectional views respectively takenalong lines I-I′, IV-IV′ and V-V′ of FIG. 2 .

FIGS. 4A to 8E illustrate a method of manufacturing a 3D semiconductormemory device according to embodiments of the inventive concept, whereinFIGS. 4A, 5A, 6A, 7A and 8A are cross-sectional views taken along theline I-I′ of FIG. 2 ; FIGS. 4B, 5B, 6B, 7B and 8B are cross-sectionalviews taken along the line II-II′ of FIG. 2 ; FIGS. 7C and 8C arecross-sectional views taken along the line III-III′ of FIG. 2 ; FIGS. 7Dand 8D are cross-sectional views taken along the line IV-IV′ of FIG. 2 ;and FIG. 8E is a cross-sectional view taken along the line V-V′ of FIG.2 .

FIGS. 9A, 9B and 9C are plan views illustrating a method ofmanufacturing a 3D semiconductor memory device according to embodimentsof the inventive concept.

FIG. 10 is a plan view further illustrating a method of manufacturing asemiconductor memory device by way of a comparative example.

FIG. 11 is a plan view illustrating a 3D semiconductor memory deviceaccording to embodiments of the inventive concept, and FIGS. 12A and 12Bare cross-sectional views taken respectively along lines I-I′ and II-II′of FIG. 11 .

FIGS. 13 and 14 are cross-sectional views taken along the line II-II′ ofFIG. 2 and illustrate a 3D semiconductor memory devices according toembodiments of the inventive concept.

FIG. 15 is a cross-sectional view taken along the line I-I′ of FIG. 2and illustrates a 3D semiconductor memory device according toembodiments of the inventive concept.

DETAILED DESCRIPTION

Throughout the written description and drawings, like reference numbersand labels are used to denote like or similar elements and/or features.Throughout the written description certain geometric terms may be usedto highlight relative relationships between elements, components and/orfeatures with respect to certain embodiments of the inventive concept.Those skilled in the art will recognize that such geometric terms arerelative in nature, arbitrary in descriptive relationship(s) and/ordirected to aspect(s) of the illustrated embodiments. Geometric termsmay include, for example: first/second/third directions; height/width;vertical/horizontal; top/bottom; higher/lower; closer/farther;thicker/thinner; proximate/distant; above/below; under/over;upper/lower; center/side; surrounding; overlay/underlay; etc.

Figure (FIG.) 1 is a perspective view illustrating a three-dimensional(3D) semiconductor memory device according to embodiments of theinventive concept.

Referring to FIG. 1 , the 3D semiconductor memory device may include aperipheral circuit structure PS, a cell array structure CS on theperipheral circuit structure PS, and through-contact(s) (not shown)vertically connecting the cell array structure CS and the peripheralcircuit structure PS. Here, the cell array structure CS may overlap, atleast on part, with the peripheral circuit structure PS when viewed inplan (i.e., when viewed from a top-down perspective).

In some embodiments, the peripheral circuit structure PS may include arow decoder, a page buffer and various control circuits. Peripherallogic circuits constituting the peripheral circuit structure PS may beintegrated on a semiconductor substrate.

The cell array structure CS may include a cell array including aplurality of memory cells three-dimensionally arranged. For example, thecell array structure CS may include a plurality of memory blocks BLK0 toBLKn. Each of the memory blocks BLK0 to BLKn may includethree-dimensionally arranged memory cells.

FIG. 2 is a plan view illustrating a 3D semiconductor memory deviceaccording to embodiments of the inventive concept. FIGS. 3A, 3B, 3C, 3Dand 3E (hereafter collectively, “FIGS. 3A to 3E”) are cross-sectionalviews variously taken along the lines I-I′, IV-IV′ and V-V′ of FIG. 2 .

Referring to FIG. 2 , the peripheral circuit structure PS and the cellarray structure CS described with reference to FIG. 1 may be disposed ona first substrate SUB. The cell array structure CS may be provided onthe peripheral circuit structure PS.

In some embodiments, the peripheral circuit structure PS on the firstsubstrate SUB may include a first row decoder region RD1, a second rowdecoder region RD2, a first page buffer region PBR1, a second pagebuffer region PBR2, and a control circuit region CC. The control circuitregion CC may be disposed between the first and second row decoderregions RD1 and RD2 and between the first and second page buffer regionsPBR1 and PBR2.

The control circuit region CC may include a first side S1 and anopposing second side S2 extending in a second direction D2 (e.g., asecond lateral direction substantially parallel with a primary surfaceof the first substrate). The first and second sides S1 and S2 may extendin a first direction D1 (e.g., a first lateral direction intersectingthe second lateral direction). The control circuit region CC may alsoinclude a third side S3 and an opposing fourth side S4 extending in thefirst direction D1. The third and fourth sides S3 and S4 may extend inthe second direction D2.

The first and second row decoder regions RD1 and RD2 may be providedadjacent to the first and second sides S1 and S2 of the control circuitregion CC, respectively. The first and second page buffer regions PBR1and PBR2 may be provided adjacent to the third and fourth sides S3 andS4 of the control circuit region CC, respectively.

The cell array structure CS on the peripheral circuit structure PS mayinclude a first lower semiconductor layer LSL1 and a second lowersemiconductor layer LSL2. The first and second lower semiconductorlayers LSL1 and LSL2 may be spaced apart in the second direction D2. Thefirst and second lower semiconductor layers LSL1 and LSL2 may beprovided on the control circuit region CC and may vertically overlapwith the control circuit region CC. Each of the first and second lowersemiconductor layers LSL1 and LSL2 may have a quadrilateral plate shapewhen viewed in plan.

The cell array structure CS may further include a first electrodestructure ST1, a second electrode structure ST2, and a mold structure MOdisposed between the first and second electrode structures ST1 and ST2.The first and second electrode structures ST1 and ST2 may be provided onthe first and second lower semiconductor layers LSL1 and LSL2,respectively. The first and second electrode structures ST1 and ST2 maybe spaced apart in the second direction D2. The mold structure MO may bedisposed between the first and second electrode structures ST1 and ST2to connect the first and second electrode structures ST1 and ST2. Eachof the first and second electrode structures ST1 and ST2 may include thememory blocks BLK0 to BLKn described above with reference to FIG. 1 .

A plurality of separation structures SPS may intersect each of the firstand second electrode structures ST1 and ST2 and may extend in the seconddirection D2. Each of the separation structures SPS may have a lineshape when viewed in plan.

A plurality of separation insulating patterns ISP may be arranged in thefirst direction D1 along a boundary between the first electrodestructure ST1 and the mold structure MO. A plurality of separationinsulating patterns ISP may be arranged in the first direction D1 alonga boundary between the second electrode structure ST2 and the moldstructure MO.

Each of the separation insulating patterns ISP may be provided at an endof the separation structure SPS. That is, an end of the separationstructure SPS may overlap with the separation insulating pattern ISP. Awidth of the separation insulating pattern ISP in the first direction D1may be greater than a width of the separation structure SPS in the firstdirection D1.

In some embodiments, the cell array structure CS may have connectionregions CNR, cell array regions CAR, and a separation region SER betweenthe cell array regions CAR. Each of the first and second electrodestructures ST1 and ST2 may be provided in the connection region CNR andthe cell array region CAR. The mold structure MO may be provided in theseparation region SER.

According to some embodiments, the peripheral logic circuitsconstituting the peripheral circuit structure PS may be freely disposedunder the cell array structure CS.

A 3D semiconductor memory device according to embodiments of theinventive concept will be described in some additional detail withreference to FIGS. 2 and 3A to 3E. The peripheral circuit structure PSincluding peripheral transistors PTR may be disposed on the firstsubstrate SUB. The first substrate SUB may include a silicon substrate,a silicon-germanium substrate, a germanium substrate, or asingle-crystalline epitaxial layer grown on a single-crystalline siliconsubstrate. The first substrate SUB may include active regions defined bya device isolation layer DIL.

The peripheral circuit structure PS may include a plurality of theperipheral transistors PTR disposed on the active regions of the firstsubstrate SUB. The peripheral transistors PTR may be disposed in thefirst and second row decoder regions RD1 and RD2, the first and secondpage buffer regions PBR1 and PBR2, and the control circuit region CC.

The peripheral circuit structure PS may include lower interconnectionlines INL on the peripheral transistors PTR, and vias VIA verticallyconnecting the lower interconnection lines INL. A peripheral contactPCNT may be provided between a lowermost one of the lowerinterconnection lines INL and the peripheral transistor PTR toelectrically connect the lowermost lower interconnection line INL andthe peripheral transistor PTR.

The peripheral circuit structure PS may further include a firstinterlayer insulating layer ILD1 covering the peripheral transistors PTRand the lower interconnection lines INL. The first interlayer insulatinglayer ILD1 may include stacked insulating layers. For example, the firstinterlayer insulating layer ILD1 may include at least one of a siliconoxide layer, a silicon nitride layer, a silicon oxynitride layer and alow-k dielectric layer.

The cell array structure CS may be provided on the first interlayerinsulating layer ILD1 of the peripheral circuit structure PS.Hereinafter, the cell array structure CS will be described in someadditional detail.

A second interlayer insulating layer ILD2 and a second substrate SL maybe provided on the first interlayer insulating layer ILD1. The secondsubstrate SL may be provided in the second interlayer insulating layerILD2. For example, the second substrate SL may have a quadrilateralplate shape when viewed in plan. The second substrate SL may support thefirst and second electrode structures ST1 and ST2 provided thereon.

The second substrate SL may include the first and second lowersemiconductor layers LSL1 and LSL2 described above. The second substrateSL may further include a source semiconductor layer SSL and an uppersemiconductor layer USL, which are sequentially stacked on each of thefirst and second lower semiconductor layers LSL1 and LSL2. Each of thefirst and second lower semiconductor layers LSL1 and LSL2, the sourcesemiconductor layer SSL and the upper semiconductor layer USL mayinclude a semiconductor material (e.g., silicon (Si), germanium (Ge),silicon-germanium (SiGe), gallium-arsenic (GaAs), indium-gallium-arsenic(InGaAs), aluminum-gallium-arsenic (AlGaAs), or any combinationthereof). Each of the first and second lower semiconductor layers LSL1and LSL2, the source semiconductor layer SSL and the upper semiconductorlayer USL may be single-crystalline, amorphous and/or poly-crystalline.For example, each of the first and second lower semiconductor layersLSL1 and LSL2, the source semiconductor layer SSL and the uppersemiconductor layer USL may include a doped, N-type poly-silicon layer.Dopant concentrations of the lower semiconductor layer LSL1 or LSL2, thesource semiconductor layer SSL and the upper semiconductor layer USL maybe different from each other.

The source semiconductor layer SSL may be disposed between the lowersemiconductor layer LSL1 or LSL2 and the upper semiconductor layer USL.The lower semiconductor layer LSL1 or LSL2 and the upper semiconductorlayer USL may be electrically connected to each other through the sourcesemiconductor layer SSL. For example, the upper semiconductor layer USLand the source semiconductor layer SSL may overlap with the lowersemiconductor layer LSL1 or LSL2 thereunder when viewed in plan.

Referring again to FIGS. 3B and 3C, a third insulating layer IL3, alower sacrificial layer LHL and a fourth insulating layer IL4 may besequentially stacked in the separation region SER. The third insulatinglayer IL3, the lower sacrificial layer LHL and the fourth insulatinglayer IL4 may be provided at the same level as the source semiconductorlayer SSL. For example, a bottom surface of the third insulating layerIL3 may be coplanar with a bottom surface of the source semiconductorlayer SSL, and a top surface of the fourth insulating layer IL4 may becoplanar with a top surface of the source semiconductor layer SSL.

Referring again to FIGS. 2 and 3A to 3E, the first electrode structureST1 and the second electrode structure ST2 may be provided on the secondsubstrate SL. Each of the first and second electrode structures ST1 andST2 may include electrodes EL stacked in a third direction D3 (e.g., avertical direction substantially orthogonal to the first direction D1and the second direction D2) on the second substrate SL. Each of thefirst and second electrode structures ST1 and ST2 may further includefirst insulating layers IL1 separating the stacked electrodes EL fromeach other. The first insulating layers IL1 and the electrodes EL may bealternately stacked in the third direction D3.

Each of the first and second electrode structures ST1 and ST2 may extendfrom the cell array region CAR into the connection region CNR. Each ofthe first and second electrode structures ST1 and ST2 may have astair-stepped structure STS in the connection region CNR. A height ofthe stair-stepped structure STS may decrease as a distance from the cellarray region CAR increases.

In each of the first and second electrode structures ST1 and ST2, alowermost electrode EL may be a lower selection line. An uppermostelectrode EL may be an upper selection line. The other electrodes ELexcept the lower and upper selection lines may be word lines.

The electrodes EL may include a conductive material. For example, theelectrodes EL may include at least one of a doped semiconductor material(e.g., doped silicon), a metal (e.g., tungsten, copper, or aluminum), aconductive metal nitride (e.g., titanium nitride or tantalum nitride)and a transition metal (e.g., titanium or tantalum). In certainembodiments, each of the first insulating layers IL1 may include asilicon oxide layer.

Each of the first and second electrode structures ST1 and ST2 mayfurther include a second insulating layer IL2. The second insulatinglayer IL2 may be selectively provided in the cell array region CAR butmay not be provided in the connection region CNR. A thickness of thesecond insulating layer IL2 may be greater than a thickness of the firstinsulating layer IL1. The second insulating layer IL2 may include thesame insulating material as the first insulating layer IL1. In certainembodiments, the second insulating layer IL2 may include a silicon oxidelayer.

A plurality of vertical channel structures VS penetrating the first andsecond electrode structures ST1 and ST2 may be provided in the cellarray region CAR. The vertical channel structures VS may be arranged inthe second direction D2. Each of the vertical channel structures VS mayinclude a vertical insulating pattern VP, a vertical semiconductorpattern SP, and a filling insulation pattern VI. The verticalsemiconductor pattern SP may be disposed between the vertical insulatingpattern VP and the filling insulation pattern VI. A conductive pad (PAD)may be provided in an upper portion of each of the vertical channelstructures VS.

The filling insulation pattern VI may have a cylindrical shape. Thevertical semiconductor pattern SP may cover an outer surface of thefilling insulation pattern VI and may extend from the lowersemiconductor layer LSL1 or LSL2 to the conductive pad in the thirddirection D3. The vertical semiconductor pattern SP may have a pipeshape having an opened top end. The vertical insulating pattern VP maycover an outer surface of the vertical semiconductor pattern SP and mayextend from the lower semiconductor layer LSL1 or LSL2 to a top surfaceof the second insulating layer IL2 in the third direction D3. Thevertical insulating pattern VP may have a pipe shape having an openedtop end. The vertical insulating pattern VP may be disposed between theelectrode structure ST1 or ST2 and the vertical semiconductor patternSP.

The vertical insulating pattern VP may be formed of a single layer or amulti-layer. In certain embodiments, the vertical insulating pattern VPmay include a data storage layer. For example, the vertical insulatingpattern VP may be a data storage layer of a NAND flash memory device andmay include a tunnel insulating layer, a charge storage layer and ablocking insulating layer.

For example, the charge storage layer may include a trap insulatinglayer, a floating gate electrode, and/or an insulating layer includingconductive nano dots. The charge storage layer may include at least oneof a silicon nitride layer, a silicon oxynitride layer, a silicon-richnitride layer, a nano-crystalline silicon layer, or a laminated traplayer. The tunnel insulating layer may include a material of which anenergy band gap is greater than that of the charge storage layer. Forexample, the tunnel insulating layer may include at least one of ahigh-k dielectric layer (e.g., an aluminum oxide layer or a hafniumoxide layer) and a silicon oxide layer. Here, the blocking insulatinglayer may include a silicon oxide layer.

The vertical semiconductor pattern SP may include a semiconductormaterial such as silicon (Si), germanium (Ge), or a combination thereof.The vertical semiconductor pattern SP may include a doped semiconductormaterial, or an undoped, intrinsic semiconductor material. The verticalsemiconductor pattern SP including the semiconductor material may beused as channels of transistors constituting a NAND cell string.

The conductive pad (PAD) may cover a top surface of the verticalsemiconductor pattern SP and a top surface of the filling insulationpattern VI. The conductive pad may include a doped semiconductormaterial and/or a conductive material. A bit line contact plug BPLG maybe electrically connected to the vertical semiconductor pattern SPthrough the conductive pad.

The source semiconductor layer SSL may be in direct contact with asidewall of a lower portion of each of the vertical semiconductorpatterns SP. The source semiconductor layer SSL may electrically connecta plurality of the vertical semiconductor patterns SP to each other.That is, the vertical semiconductor patterns SP may be electricallyconnected to the second substrate SL. The second substrate SL mayfunction as sources of memory cells. A common source voltage may beapplied to the second substrate SL.

The 3D semiconductor memory device according to embodiments may be a 3DNAND flash memory device. NAND cell strings may be integrated at theelectrode structures ST1 and ST2 on the lower semiconductor layers LSL1and LSL2. That is, the first and second electrode structures ST1 and ST2and the vertical channel structures VS penetrating them may constitutememory cells three-dimensionally arranged on the second substrate SL.The electrodes EL of the first and second electrode structures ST1 andST2 may be used as gate electrodes of memory transistors (i.e., thememory cells).

The mold structure MO may be provided in the separation region SER. Themold structure MO may be disposed between the first and second electrodestructures ST1 and ST2 to physically connect the first and secondelectrode structures ST1 and ST2. The mold structure MO may extend inthe first direction D1 between the first and second electrode structuresST1 and ST2 when viewed in plan.

The mold structure MO may include sacrificial layers HL stacked in thethird direction D3 on the second interlayer insulating layer ILD2. Thefirst insulating layers IL1 may extend between the stacked sacrificiallayers HL to separate the sacrificial layers HL from each other. Thatis, the first insulating layers IL1 and the sacrificial layers HL of themold structure MO may be alternately stacked in the third direction D3.The second insulating layer IL2 may be provided in an uppermost portionof the mold structure MO. The mold structure MO may share the first andsecond insulating layers IL1 and IL2 with the first and second electrodestructures ST1 and ST2.

The sacrificial layers HL may be provided at the same levels as theelectrodes EL of the first and second electrode structures ST1 and ST2,respectively. That is, the sacrificial layer HL of the mold structure MOmay physically connect the electrode EL of the first electrode structureST1 and the electrode EL of the second electrode structure ST2. Thesacrificial layers HL may include an insulating material such as siliconnitride or silicon oxynitride. Since the first insulating layers ILL thesecond insulating layer IL2 and the sacrificial layers HL are formed ofthe insulating materials, the mold structure MO may be an insulator.

Referring to FIG. 3B, dummy structures DS penetrating the mold structureMO may be provided in the separation region SER. The dummy structure DSmay include a vertical insulating pattern VP, a vertical semiconductorpattern SP, and a filling insulation pattern VI, like the verticalchannel structure VS described above. However, the dummy structure DSmay not function as channels of memory cells, unlike the verticalchannel structure VS. The dummy structure DS is not electricallyconnected to bit lines BL and upper interconnection lines UIL, asdescribed hereafter. That is, the dummy structure DS is just that, adummy structure that does not perform circuit functions. However, thedummy structures DS may function as pillars (i.e., supporters) thatphysically support, at least in part, the mold structure MO.

A third interlayer insulating layer ILD3 may be provided on the secondsubstrate SL. The third interlayer insulating layer ILD3 may cover thestair-stepped structures STS of the first and second electrodestructures ST1 and ST2. A fourth interlayer insulating layer ILD4 may beprovided on the third interlayer insulating layer ILD3.

A plurality of the separation structures SPS may penetrate each of thefirst and second electrode structures ST1 and ST2. The separationstructures SPS may be arranged in parallel and extend in the seconddirection D2. For example, one electrode EL may be horizontally dividedinto a plurality of electrodes EL by the separation structures SPS.(See, e.g., FIG. 3E). The plurality of electrodes EL divided by theseparation structures SPS may be arrange din parallel and extend in thesecond direction D2.

The separation structure SPS may penetrate the electrode structure ST1or ST2 to extend to the lower semiconductor layer LSL1 or LSL2. Theseparation structure SPS may include an insulating material such assilicon oxide.

A plurality of the separation insulating patterns ISP may penetrate themold structure MO. Referring to FIG. 3C, the separation insulatingpattern ISP may contact with an end EN of the separation structure SPSextending to the mold structure MO. The separation insulating patternISP may penetrate the mold structure MO but may not extend to the lowersemiconductor layer LSL1 or LSL2. That is, a bottom surface of theseparation insulating pattern ISP may be higher than a bottom surface ofthe separation structure SPS. Meanwhile, a top surface of the separationinsulating pattern ISP, a top surface of the separation structure SPSand a top surface of the fourth interlayer insulating layer ILD4 may becoplanar.

Referring to FIG. 3D, a maximum width of the separation insulatingpattern ISP in the first direction D1 may be a first width W1. Referringto FIG. 3E, a maximum width of the separation structure SPS in the firstdirection D1 may be a second width W2. The first width W1 may be greaterthan the second width W2. That is, the separation insulating pattern ISPmay surround the end of the separation structure SPS, as illustrated inFIG. 2 .

Bit line contact plugs BPLG may penetrate the fourth interlayerinsulating layer ILD4 so as to be connected to the conductive pads PAD,respectively. A plurality of bit lines BL may be disposed on the fourthinterlayer insulating layer ILD4. The bit lines BL may extend in thefirst direction D1 in parallel to each other. Each of the bit lines BLmay be electrically connected to the vertical semiconductor pattern SPthrough the bit line contact plug BPLG.

Referring to FIG. 3A, a plurality of cell contact plugs PLG may beprovided in the connection region CNR. The cell contact plugs PLG maypenetrate the third and fourth interlayer insulating layers ILD3 andILD4 so as to be connected to the electrodes EL constituting thestair-stepped structure STS, respectively. A plurality of upperinterconnection lines UIL may be disposed on the fourth interlayerinsulating layer ILD4. Each of the upper interconnection lines UIL maybe electrically connected to the electrode EL through the cell contactplug PLG.

Referring to FIG. 3A, at least one through-contact TVS may be providedon the first and second row decoder regions RD1 and RD2. Thethrough-contact TVS may penetrate the fourth interlayer insulating layerILD4, the third interlayer insulating layer ILD3 and the secondinterlayer insulating layer ILD2 so as to be connected to an uppermostlower interconnection line INL. The first and second row decoder regionsRD1 and RD2 may be electrically connected to the upper interconnectionline UIL through the through-contact TVS. That is, the electrode EL ofthe cell array structure CS may be electrically connected to the rowdecoder of the peripheral circuit structure PS through thethrough-contact TVS.

In some embodiments, the first and second row decoder regions RD1 andRD2 may include pass transistors. The word lines of the cell arraystructure CS may be connected to the row decoder through the passtransistors.

Referring to FIGS. 3B and 3C, at least one through-contact TVS may beprovided in the separation region SER. The through-contact TVS maypenetrate the mold structure MO to connect an uppermost lowerinterconnection line INL. The control circuit region CC may beelectrically connected to the bit line BL through the through-contactTVS.

In some embodiments, the mold structure MO may be provided between thefirst and second electrode structures ST1 and ST2 to physically supportthe first and second electrode structures ST1 and ST2. Thus, it ispossible to prevent the first and second electrode structures ST1 andST2 from collapsing or leaning during formation of the electrodes EL inthe first and second electrode structures ST1 and ST2.

The first and second electrode structures ST1 and ST2 may beelectrically isolated by the mold structure MO. The first row decoderregion RD1 may be disposed at one side of the first electrode structureST1, and the second row decoder region RD2 may be disposed at one sideof the second electrode structure ST2. Thus, the first and secondelectrode structures ST1 and ST2 may operate as memory blocksindependent of each other. As a result, the number of the memory blocksmay be increased in the 3D semiconductor memory device accordingembodiments of the inventive concept, and one or more of the memoryblocks may be used as a repair block.

In some embodiments, the cell array structure CS may be divided into thefirst and second electrode structures ST1 and ST2 by the mold structureMO of the separation region SER. Since the mold structure MO is providedin only the cell array structure CS, the peripheral circuit structure PSunder the separation region SER may not be affected by the separationregion SER but may be maintained in a single circuit structure. As aresult, an area occupied by the control circuit region CC may be widenedor increased. The control circuit region CC may realize global internalconnection(s) under the first and second electrode structures ST1 andST2. That is, a first peripheral transistor PTRa under the firstelectrode structure ST1 and a second peripheral transistor PTRb underthe second electrode structure ST2 may be electrically connected to eachother through the lower interconnection line INL extending or crossingunder the mold structure MO. (See, e.g., FIG. 3B). Thus, according tocertain embodiments of the inventive concept, design efficiency of theperipheral circuit may be improved.

FIGS. 4A, 4B, 5A, 5B, 6A, 6B, 7A, 7B, 7C, 7D, 8A, 8B, 8C, 8D and 8Ecollectively illustrate method(s) of manufacturing a 3D semiconductormemory device according to embodiments of the inventive concept. Here,FIGS. 4A, 5A, 6A, 7A and 8A are cross-sectional views taken along theline I-I′ of FIG. 2 ; FIGS. 4B, 5B, 6B, 7B and 8B are cross-sectionalviews taken along the line II-II′ of FIG. 2 ; FIGS. 7C and 8C arecross-sectional views taken along the line of FIG. 2 ; FIGS. 7D and 8Dare cross-sectional views taken along the line IV-IV′ of FIG. 2 ; andFIG. 8E is a cross-sectional view taken along the line V-V′ of FIG. 2 .

Referring to FIGS. 2, 4A and 4B, a peripheral circuit structure PS maybe formed on a first substrate SUB. The formation of the peripheralcircuit structure PS may include forming peripheral transistors PTR onthe first substrate SUB, and forming lower interconnection lines INL onthe peripheral transistors PTR.

For example, the formation of the peripheral transistors PTR may includeforming a device isolation layer DIL in the first substrate SUB todefine active regions, forming a gate insulating layer and gateelectrodes on the active regions, and injecting dopants into the activeregions to form source/drain regions.

A first interlayer insulating layer ILD1 covering the peripheraltransistors PTR and the lower interconnection lines INL may be formed.First and second lower semiconductor layers LSL1 and LSL2 may be formedon the first interlayer insulating layer ILD1. The formation of thefirst and second lower semiconductor layers LSL1 and LSL2 may includeforming a lower semiconductor layer on the first interlayer insulatinglayer ILD1, and patterning the lower semiconductor layer inquadrilateral plate shapes.

The first and second lower semiconductor layers LSL1 and LSL2 mayinclude a semiconductor material such as poly-silicon. The first andsecond lower semiconductor layers LSL1 and LSL2 may be spaced apart inthe second direction D2. An insulating layer may be formed to fill aspace between the first and second lower semiconductor layers LSL1 andLSL2.

A third insulating layer IL3, a lower sacrificial layer LHL and a fourthinsulating layer IL4 may be sequentially formed on the first and secondlower semiconductor layers LSL1 and LSL2. For example, each of the thirdand fourth insulating layers IL3 and IL4 may include a silicon oxidelayer, and the lower sacrificial layer LHL may include a silicon nitridelayer or a silicon oxynitride layer.

An upper semiconductor layer USL may be formed on the fourth insulatinglayer IL4. The upper semiconductor layer USL may be patterned to bedivided into segments overlapping with the first and second lowersemiconductor layers LSL1 and LSL2, respectively. These segments may bereferred to as upper semiconductor layers USL. An insulating layer maybe formed to fill a space between the upper semiconductor layers USL.

The first and second lower semiconductor layers LSL1 and LSL2, the lowersacrificial layer LHL and the upper semiconductor layers USL mayconstitute a second substrate SL. The insulating layers formed at thesame level as the second substrate SL may constitute a second interlayerinsulating layer ILD2.

Referring to FIGS. 2, 5A and 5B, a mold structure MO may be formed onthe second substrate SL. For example, first insulating layers IL1 andsacrificial layers HL may be alternately stacked on the second substrateSL to form the mold structure MO. A second insulating layer IL2 may beformed at the uppermost layer of the mold structure MO.

The first insulating layers ILL the sacrificial layers HL and the secondinsulating layer IL2 may be deposited using a thermal chemical vapordeposition (thermal CVD) process, a plasma-enhanced CVD process, aphysical CVD process, and/or an atomic layer deposition (ALD) process.For example, each of the first insulating layers IL1 may include asilicon oxide layer, and each of the sacrificial layers HL may include asilicon nitride layer or a silicon oxynitride layer.

A stair-stepped structure STS may be formed at the mold structure MO ofthe connection region CNR. For example, a cycle process may be performedon the mold structure MO to form the stair-stepped structure STS in theconnection region CNR. The formation of the stair-stepped structure STSmay include forming a mask pattern (not shown) on the mold structure MO,and repeatedly performing a cycle using the mask pattern a plurality oftimes. The cycle may include a process of etching a portion of the moldstructure MO by using the mask pattern as an etch mask, and a trimmingprocess of shrinking the mask pattern.

Referring to FIGS. 2, 6A and 6B, a third interlayer insulating layerILD3 may be formed on the mold structure MO. The formation of the thirdinterlayer insulating layer ILD3 may include forming a thick insulatinglayer covering the mold structure MO, and performing a planarizationprocess on the thick insulating layer until the second insulating layerIL2 is exposed. Thus, the third interlayer insulating layer ILD3 maycover the stair-stepped structure STS.

Channel holes CH may be formed to penetrate the mold structure MO of thecell array region CAR. The channel holes CH may expose the first andsecond lower semiconductor layers LSL1 and LSL2. A bottom surface ofeach of the channel holes CH may be located at a level between a bottomsurface and a top surface of the lower semiconductor layer LSL1 or LSL2.For example, the formation of the channel holes CH may include forming amask pattern (not shown) having openings defining the channel holes CHon the mold structure MO, and anisotropically etching the mold structureMO using the mask pattern as an etch mask.

The channel holes CH may be arranged in a line or zigzag form in onedirection when viewed in plan. The anisotropic etching process forforming the channel holes CH may be a plasma etching process, a reactiveion etching (RIE) process, an inductively coupled plasma reactive ionetching (ICP-RIE) process, or an ion beam etching (IBE) process.

Dummy holes DH may be formed to penetrate the mold structure MO of theseparation region SER. The dummy holes DH may be formed simultaneouslywith the channel holes CH. That is, the channel holes CH and the dummyholes DH may be formed at the same time by the anisotropic etchingprocess described above. The channel holes CH and the dummy holes DH mayexhaust gas remaining in the mold structure MO.

Vertical channel structures VS may be formed in the channel holes CH,respectively. The formation of the vertical channel structure VS mayinclude sequentially forming a vertical insulating layer, a verticalsemiconductor layer and a filling insulation layer on an inner surfaceof the channel hole CH, and performing a planarization process until atop surface of the second insulating layer IL2 is exposed. The verticalinsulating layer and the vertical semiconductor layer may be conformallyformed.

That is, a vertical insulating pattern VP covering the inner surface ofthe channel hole CH may be formed. The vertical insulating pattern VPmay have a pipe shape having an opened top end. The vertical insulatingpattern VP may include a data storage layer. A vertical semiconductorpattern SP covering an inner surface of the vertical insulating patternVP may be formed. The vertical semiconductor pattern SP may have a pipeshape having an opened top end. A filling insulation pattern VI fillingthe inside of the pipe shape of the vertical semiconductor pattern SPmay be formed. The vertical insulating pattern VP, the verticalsemiconductor pattern SP and the filling insulation pattern VI mayconstitute the vertical channel structure VS. A conductive pad (PAD) maybe formed on each of the vertical channel structures VS.

Dummy structures DS may be formed in the dummy holes DH, respectively.The dummy structures DS may be formed simultaneously with the verticalchannel structures VS. Thus, each of the dummy structures DS may includethe same material(s) as the vertical channel structure VS (e.g., thevertical insulating pattern VP), the vertical semiconductor pattern SPand the filling insulation pattern VI.

FIGS. 9A, 9B and 9C are respective plan views illustrating a method ofmanufacturing a 3D semiconductor memory device according to embodimentsof the inventive concept. With reference to FIGS. 9A, 9B and 9C, amethod of replacing the sacrificial layers HL of the cell array regionCAR with electrodes EL while leaving the sacrificial layers HL of themold structure MO of the separation region SER will be described.

Referring to FIGS. 2, 7A, 7B, 7C, 7D and 9A, a fourth interlayerinsulating layer ILD4 may be formed on the mold structure MO and thethird interlayer insulating layer ILD3. Separation insulating patternsISP may be formed at a boundary between the cell array region CAR andthe separation region SER by using a process of patterning the moldstructure MO. The separation insulating patterns ISP may be arranged inthe first direction D1 along the boundary. (See, e.g., FIG. 9A).

That is, the formation of the separation insulating patterns ISP mayinclude forming through-holes penetrating the mold structure MO, andfilling the through-holes with an insulating material. The through-holesmay be formed by anisotropically etching the mold structure MO until theupper semiconductor layers USL are exposed.

Referring to FIGS. 2, 8A, 8B, 8C, 8D, 8E and 9B, the mold structure MOmay be patterned to form a plurality of cutting trenches CTR penetratingthe mold structure MO. The cutting trenches CTR may extend in the seconddirection D2 in parallel to each other in the connection region CNR andthe cell array region CAR. The cutting trenches CTR may not be formed inthe separation region SER.

The cutting trenches CTR may expose the first and second lowersemiconductor layers LSL1 and LSL2. The cutting trench CTR may exposethe sacrificial layers HL of the mold structure MO. (See, e.g., FIG.8E). The cutting trench CTR may expose a sidewall of the lowersacrificial layer LHL.

Referring to FIG. 9B, an end EN of each of the cutting trenches CTR maybe formed in the separation insulating pattern ISP. A portion of theseparation insulating pattern ISP may be etched by an etching processfor forming the cutting trench CTR. However, since a width of theseparation insulating pattern ISP is greater than a width of the cuttingtrench CTR, the separation insulating pattern ISP may surround the endEN of the cutting trench CTR when viewed in plan. As a result, the endEN of the cutting trench CTR may be surrounded by the separationinsulating pattern ISP and thus may not expose the sacrificial layers HLof the mold structure MO.

Referring to FIGS. 2, 8A, 8B, 8C, 8D and 8E, the lower sacrificial layerLHL exposed by the cutting trenches CTR may be replaced with a sourcesemiconductor layer SSL. That is, the lower sacrificial layer LHLexposed by the cutting trenches CTR may be selectively removed. A lowerportion of the vertical insulating pattern VP of each of the verticalchannel structures VS may be exposed by the removal of the lowersacrificial layer LHL.

The removal of the lower sacrificial layer LHL may be isotropicallyperformed using a wet etching process. Thus, the lower sacrificial layerLHL adjacent to the cutting trench CTR may be removed, but the lowersacrificial layer LHL spaced apart from the cutting trench CTR may notbe removed but may remain. For example, as illustrated in FIGS. 8B and8C, the lower sacrificial layer LHL located in a central region of theseparation region SER may not be removed but may remain.

The lower portion of the vertical insulating pattern VP exposed by theremoval of the lower sacrificial layer LHL may be selectively removed.Thus, a lower portion of the vertical semiconductor pattern SP may beexposed. The third insulating layer IL3 and the fourth insulating layerIL4 may be removed together during the removal of the lower portion ofthe vertical insulating pattern VP.

The source semiconductor layer SSL may be formed in a space formed bythe removal of the lower sacrificial layer LHL. The source semiconductorlayer SSL may be in direct contact with the exposed lower portion of thevertical semiconductor pattern SP. The source semiconductor layer SSLmay be in direct contact with the lower semiconductor layer LSL1 or LSL2thereunder. The source semiconductor layer SSL may be in direct contactwith the upper semiconductor layer USL thereon.

The formation of the source semiconductor layer SSL may use a process ofselectively depositing a semiconductor material (e.g., poly-silicon) inonly the space formed by the removal of the lower sacrificial layer LHLthrough the cutting trench CTR. Thus, the cutting trench CTR may not befilled with the semiconductor material but may remain as an empty space.

Referring to FIGS. 2, 3A, 3B, 3C, 3D, 3E and 9C, the sacrificial layersHL exposed by the cutting trenches CTR may be replaced with electrodesEL, respectively, and thus first and second electrode structures ST1 andST2 may be formed. In detail, the sacrificial layers HL exposed throughthe cutting trenches CTR may be selectively removed. The electrodes ELmay be formed in spaces respectively resulting from the removal of thesacrificial layers HL.

As described above, the separation insulating patterns ISP may preventthe sacrificial layers HL of the separation region SER from beingexposed by the cutting trenches CTR. Thus, the sacrificial layers HL ofthe separation region SER may not be replaced with the electrodes EL butmay remain. That is, the mold structure MO of the separation region SERmay remain.

During the formation of the electrodes EL, a stack structure may becomestructurally unstable by removal of the sacrificial layers HL of thecell array region CAR. This result may occur because cavities are formedin the stack structure. In some embodiments, however, the sacrificiallayers HL of the mold structure MO of the separation region SER may notbe removed, but may remain. Accordingly, the mold structure MO of theseparation region SER may function as a support of the stack structure.Thus, it is possible to prevent the first and second electrodestructures ST1 and ST2 from collapsing or leaning during the formationof the first and second electrode structures ST1 and ST2.

Separation structures SPS may be formed by filling the cutting trenchesCTR with an insulating material. The separation structures SPS maynode-separate the electrodes EL arranged at the same level.

At least one through-contact TVS may be formed on the first and secondrow decoder regions RD1 and RD2. At least one through-contact TVS may beformed in the separation region SER. The through-contacts TVS may extendfrom the fourth interlayer insulating layer ILD4 to the peripheralcircuit structure PS.

Bit line contact plugs BPLG may be formed to penetrate the fourthinterlayer insulating layer ILD4. The bit line contact plugs BPLG may beconnected to the conductive pads PAD, respectively. Cell contact plugsPLG may be formed to penetrate the third and fourth interlayerinsulating layers ILD3 and ILD4. The cell contact plugs PLG may beconnected to the electrodes EL, respectively. Bit lines BL and upperinterconnection lines UIL may be formed on the fourth interlayerinsulating layer ILD4. The bit lines BL may be electrically connected tothe bit line contact plugs BPLG, and the upper interconnection lines UILmay be electrically connected to the cell contact plugs PLG.

FIG. 10 is a plan view further illustrating a method of manufacturing asemiconductor memory device by way of a comparative example. Here, aprocess defect—which may occur when the separation insulating patternsISP included in certain embodiments of the inventive concept areomitted—will now be described with reference to FIG. 10 .

The sacrificial layer HL adjacent to the cutting trenches CTR may beremoved through the cutting trenches CTR by an isotropic etchingprocess. Since the separation insulating pattern ISP does not exist, theend EN of the cutting trench CTR may also expose the sacrificial layerHL. Thus, a portion of the sacrificial layer HL of the separation regionSER may be removed by the isotropic etching process.

The electrodes EL may be formed in a region formed by the removal of thesacrificial layer HL. Meanwhile, an electrode EL may also be formed inthe separation region SER. Thus, the electrode EL of the separationregion SER may connect the electrodes EL of the cell array region CAR.Therefore, the electrodes EL may not be node-separated, but instead maybe connected one with another.

FIG. 11 is a plan view illustrating a 3D semiconductor memory deviceaccording to embodiments of the inventive concept. FIGS. 12A and 12B arecross-sectional views respectively taken along lines I-I′ and II-II′ ofFIG. 11 . The previous (and commonly applicable) description of theembodiments illustrated in FIGS. 2, 3A, 3B, 3C, 3D and 3E will beomitted here for brevity. Accordingly, only material differences betweenthe embodiments of FIGS. 11A, 11B and 11C and the embodiments of FIGS.2, 3A, 3B, 3C, 3D and 3E will be described.

Referring to FIGS. 11, 12A and 12B, separation insulating patterns ISPmay intersect the separation region SER in the second direction D2. Theseparation insulating pattern ISP may have a line shape extending in thesecond direction D2. The separation insulating pattern ISP may have adumbbell shape having a greater width at the boundary between the cellarray region CAR and the separation region SER.

As illustrated in FIG. 12B, the separation insulating patterns ISP maypenetrate the mold structure MO. At least one through-contact TVS maypenetrate the separation insulating pattern ISP so as to be connected tothe peripheral circuit structure PS.

FIGS. 13 and 14 are cross-sectional views taken along the line II-II′ ofFIG. 2 and illustrate 3D semiconductor memory devices according toembodiments of the inventive concept. As before, only materialdifferences between the embodiments of FIGS. 13 and 14 and theembodiments of FIGS. 2, 3A, 3B. 3C, 3D and 3E will be described.

Referring to FIG. 13 , dummy contacts DTVS may be provided in theseparation region SER. The dummy contacts DTVS may penetrate the moldstructure MO so as to be connected to the upper semiconductor layer USL.However, the dummy contacts DTVS may not be electrically connected tothe bit lines BL and the upper interconnection lines UIL and thus may bedummies not performing a circuit function. The formation of the dummycontacts DTVS may include a process of forming contact holes penetratingthe mold structure MO. A process by-product (e.g., a gas) remaining inthe mold structure MO may be exhausted to the outside through thecontact holes.

Referring to FIG. 14 , a third lower semiconductor layer LSL3 may beprovided in the separation region SER. The third lower semiconductorlayer LSL3 may be disposed between the first and second lowersemiconductor layers LSL1 and LSL2. A through-contact TVS may beconnected to the third lower semiconductor layer LSL3. Thethrough-contact TVS may be electrically connected to a ground line GILthereon. Thus, a ground voltage may be applied to the third lowersemiconductor layer LSL3. Since the ground voltage is applied to thethird lower semiconductor layer LSL3, a coupling phenomenon between thefirst and second lower semiconductor layers LSL1 and LSL2 may beprevented.

FIG. 15 is a cross-sectional view taken along the line I-I′ of FIG. 2and illustrates a 3D semiconductor memory device according toembodiments of the inventive concept. Once again, only materialdifferences between the embodiment of FIG. 15 and the embodiments ofFIGS. 2, 3A, 3B, 3C, 3D and 3E will be described.

Referring to FIG. 15 , each of first and second electrode structures ST1and ST2 may include a lower structure STa and an upper structure STb onthe lower structure STa.

The lower structure STa may include first electrodes EL1 stacked in thethird direction D3 on the second substrate SL. The lower structure STamay further include first insulating layers IL1 separating the stackedfirst electrodes EL1 from each other. The first insulating layers IL1and the first electrodes EL1 of the lower structure STa may bealternately stacked in the third direction D3. A second insulating layerIL2 may be provided in an uppermost portion of the lower structure STa.The second insulating layer IL2 may be thicker than each of the firstinsulating layers IL1.

The upper structure STb may include second electrodes EL2 stacked in thethird direction D3 on the lower structure STa. The upper structure STbmay further include fifth insulating layers IL5 separating the stackedsecond electrodes EL2 from each other. The fifth insulating layers IL5and the second electrodes EL2 of the upper structure STb may bealternately stacked in the third direction D3. A sixth insulating layerIL6 may be provided in an uppermost portion of the upper structure STb.The sixth insulating layer IL6 may be thicker than each of the fifthinsulating layers IL5.

Each of vertical channel structures VS may include a first verticalextension penetrating the lower structure STa, a second verticalextension penetrating the upper structure STb, and an expansion portionEXP between the first and second vertical extensions. The expansionportion EXP may be provided in the second insulating layer IL2. Adiameter of the vertical channel structure VS may increase sharply atthe expansion portion EXP.

In 3D semiconductor memory devices according to embodiments of theinventive concept, a process defect in which electrode structurescollapse or lean may be prevented by the use of a mold structure asdescribed above. The electrode structures may operate as the memoryblocks independent of each other, and thus one or more may be used asrepair block(s). The cell array region may include the memory blocksseparated from each other, but the peripheral circuit region thereundermay be realized as a single global connection region. Thus, the designefficiency of the peripheral circuit may be improved.

While the inventive concept have been described with reference toexample embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the scope of the inventive concept. Here, the scope of theinventive concept should be offered the broadest permissibleinterpretation of the following claims and their equivalents.

What is claimed is:
 1. A three-dimensional (3D) semiconductor memorydevice comprising: a peripheral circuit structure including a first rowdecoder region, a second row decoder region, and a control circuitregion between the first row decoder region and the second row decoderregion; a first electrode structure and a second electrode structure onthe peripheral circuit structure, wherein the first electrode structureand the second electrode structure are spaced apart in a first directionand each respectively includes stacked electrodes; a mold structure onthe peripheral circuit structure, wherein the mold structure is disposedbetween the first electrode structure and the second electrode structureand includes stacked sacrificial layers; and vertical channel structurespenetrating the first electrode structure and the second electrodestructure, wherein, when viewed in plan, the mold structure has a lineshape that extends in a first direction, wherein the mold structure isconfigured to separate the first electrode structure and the secondelectrode structure from each other in a second direction.
 2. The 3Dsemiconductor memory device of claim 1, further comprising: a dummystructure penetrating the mold structure; and a bit line electricallyconnected to at least one of the vertical channel structures, whereinthe dummy structure is not electrically connected to the bit line. 3.The 3D semiconductor memory device of claim 2, wherein the dummystructure includes at least one same material as the vertical channelstructure.
 4. The 3D semiconductor memory device of claim 1, furthercomprising: a through-contact penetrating the mold structure to extendto the peripheral circuit structure, wherein the control circuit regionincludes peripheral transistors and lower interconnection lines on theperipheral transistors, and the through-contact is electricallyconnected to an uppermost one of the lower interconnection lines.
 5. The3D semiconductor memory device of claim 1, further comprising: a firstlower semiconductor layer between the peripheral circuit structure andthe first electrode structure; and a second lower semiconductor layerbetween the peripheral circuit structure and the second electrodestructure, wherein the first lower semiconductor layer and the secondlower semiconductor layer are spaced apart in the second direction. 6.The 3D semiconductor memory device of claim 5, further comprising: athird lower semiconductor layer between the peripheral circuit structureand the mold structure; a through-contact penetrating the mold structureto connect the third lower semiconductor layer; and a ground line on thethrough-contact and electrically connecting the through-contact.
 7. The3D semiconductor memory device of claim 1, wherein the sacrificial layerof the mold structure physically connects an electrode of the firstelectrode structure to an electrode of the second electrode structure.8. The 3D semiconductor memory device of claim 1, wherein the first rowdecoder region is adjacent to a side of the first electrode structure,and the second row decoder region is adjacent to a side of the secondelectrode structure.
 9. The 3D semiconductor memory device of claim 1,wherein the control circuit region comprises: a first peripheraltransistor provided under the first electrode structure; a secondperipheral transistor provided under the second electrode structure; anda lower interconnection line crossing under the mold structure, whereinthe first peripheral transistor electrically connects the secondperipheral transistor through the lower interconnection line.
 10. The 3Dsemiconductor memory device of claim 1, further comprising: a firstseparation structure intersecting the first electrode structure in thesecond direction; and a second separation structure intersecting thesecond electrode structure in the second direction.
 11. Athree-dimensional (3D) semiconductor memory device comprising: asubstrate; a peripheral circuit structure on the substrate; an electrodestructure including electrodes stacked on the peripheral circuitstructure; a mold structure intersecting the electrode structure andextending in a first direction, the mold structure dividing theelectrode structure into a first electrode structure and a secondelectrode structure in a second direction and extending in the firstdirection; vertical channel structures penetrating the first electrodestructure and the second electrode structure; and a through-contactpenetrating the mold structure to extend to the peripheral circuitstructure, wherein the mold structure includes first insulating layersand second insulating layers that are alternately stacked on theperipheral circuit structure.
 12. The 3D semiconductor memory device ofclaim 11, wherein the peripheral circuit structure includes peripheraltransistors and lower interconnection lines on the peripheraltransistors, and wherein the through-contact is electrically connectedto an uppermost one of the lower interconnection lines.
 13. The 3Dsemiconductor memory device of claim 11, wherein the peripheral circuitstructure includes a first row decoder region, a second row decoderregion, and a control circuit region between the first row decoderregion and the second row decoder region, and wherein the first rowdecoder region is adjacent to a side of the first electrode structure,and the second row decoder region is adjacent to a side of the secondelectrode structure.
 14. The 3D semiconductor memory device of claim 11,wherein, when viewed in plan, the mold structure has a line shape thatextends in the first direction.
 15. The 3D semiconductor memory deviceof claim 11, further comprising: a dummy structure penetrating the moldstructure, wherein the dummy structure includes at least one samematerial as the vertical channel structure.
 16. A three-dimensional (3D)semiconductor memory device comprising: a substrate; a peripheralcircuit structure on the substrate; an electrode structure includingelectrodes stacked on the peripheral circuit structure; a mold structureintersecting the electrode structure and extending in a first direction,the mold structure dividing the electrode structure into a firstelectrode structure and a second electrode structure in a seconddirection and extending in the first direction; vertical channelstructures penetrating the first electrode structure and the secondelectrode structure; and a through-contact penetrating the moldstructure to extend to the peripheral circuit structure, wherein each ofthe vertical channel structures includes a first vertical extension, asecond vertical extension on the first vertical extension, and anexpansion portion between the first and second vertical extensions,wherein a diameter of each of the vertical channel structures changesabruptly at the expansion portion, and wherein a diameter of thethrough-contact continuously varies along a vertical direction.
 17. The3D semiconductor memory device of claim 16, wherein the peripheralcircuit structure includes peripheral transistors and lowerinterconnection lines on the peripheral transistors, and wherein thethrough-contact is electrically connected to an uppermost one of thelower interconnection lines.
 18. The 3D semiconductor memory device ofclaim 16, wherein the peripheral circuit structure includes a first rowdecoder region, a second row decoder region, and a control circuitregion between the first row decoder region and the second row decoderregion, and wherein the first row decoder region is adjacent to a sideof the first electrode structure, and the second row decoder region isadjacent to a side of the second electrode structure.
 19. The 3Dsemiconductor memory device of claim 16, wherein, when viewed in plan,the mold structure has a line shape that extends in the first direction.20. The 3D semiconductor memory device of claim 16, further comprising:a dummy structure penetrating the mold structure, wherein the dummystructure includes at least one same material as the vertical channelstructure.